This relates to communication networks, and more particularly, to using a controller to manage hardware address discovery in network.
Packet-based networks such as the internet and local data networks that are connected to the internet include network switches. Network switches are used in forwarding packets from packet sources to packet destinations. The packets may be sometimes referred to as frames.
It can be difficult or impossible to control the switches of one vendor using the equipment of another vendor. This is because the switch equipment of one vendor may use a different operating system and set of control procedures than the switch equipment of another vendor. To address the challenges associated with controlling different types of switch platforms, cross-platform protocols have been developed. These protocols allow centralized control of otherwise incompatible switches.
Cross-platform controller clients can be included on the switches in a network. The controller clients are able to communicate with a corresponding controller server over network paths. Because the controller clients can be implemented on a variety of switch hardware, it is possible for a single controller to control switch equipment that might otherwise be incompatible.
End hosts that are coupled to network switches have network addresses and hardware addresses. A first end host communicates with a second end host by sending network packets with header fields that identify a network address and a hardware address of the second end host. In some scenarios, the end hosts have access to the network addresses of other end hosts but not to their hardware addresses. To discover the hardware address of the second end host, the first end host can flood the network with an address resolution protocol (ARP) request that identifies the second end host by its network address and requests that the second end host reply with its hardware address.
Flooding of a network to send ARP requests can undesirably load the network with unnecessary network traffic because the ARP requests can be sent to many end hosts that ignore the requests (e.g., because those end hosts are not associated with the network address identified in the ARP requests). The forwarding of unnecessary ARP requests can impact performance of the network. It would therefore be desirable to be able to provide improved arrangements for performing address discovery of end hosts in a network.